package dongtai;

public class yiyisanqi {
    public static int tribonacci(int n) {
        int[] dp=new int[n+1];
        if(n==0||n==1){
            return n;
        }
        dp[0]=0;
        dp[1]=1;
        dp[2]=1;
        if(n<=2){
            return dp[n];
        }
        for(int i=3;i<=n;i++){
            dp[i]=dp[i-1]+dp[i-2]+dp[i-3];
        }
        return dp[n];
    }

    public static void main(String[] args) {
        int m=0;
        int tribonacci = tribonacci(1);
        System.out.println(tribonacci);
    }
}
